The present invention relates generally to stump grinding machines of the type having a grinding wheel located at the distal end of a movable boom. More particularly, the invention relates to improvements in the replaceable cutting tools that are mounted on the machine""s grinding wheel.
Stump grinding machines are widely used to remove tree stumps. The stump is removed by a driven grinding wheel located at the distal end of a movable boom. Typically, the grinding wheel is swept back and forth in a generally horizontal plane across the stump. With each sweep the grinding wheel may be lowered or moved forward slightly to remove more of the stump and the final sweeps may be below ground level to ensure elimination of the entire stump. Details regarding the structure and operation of a stump cutter can be found in U.S. Pat. No. 6,003,570, incorporated herein by reference.
The grinding wheel includes a plurality of brackets or other mechanisms for receipt of cutting tools. The cutting tools are mounted to the grinding wheel in pockets or channels formed in the brackets so that the cutting tip portion of the cutting tool extends radially outward from its respective bracket to perform the grinding function. It will be appreciated, however, that these cutting tools must often be replaced due to normal and wear and tear. For example, both the shaft portion of the cutting tool and the cutting tip of the cutting tool (which is typically a carbide tip) may be subject to breakage or wear. In some cases, the manufacturer of the stump grinding machine may configure the grinding wheel and the corresponding brackets to maximize the stump grinding potential of the wheel and extend the life of the cutting tools.
One example of a prior art cutting tool and bracket that is conventional in many respects is shown in FIG. 4 of U.S. Pat. No. 5,279,345, to LeMaux et al. The cutting tool defines a substantially uniform crosssection extending from its base end towards its cutting tip. The cutting tool may include a bend toward the cutting tip end so that the cutting wheel defines a full cut pattern when all of the cutting tools are properly installed. The conventional receiving bracket includes a cutting tool receiving channel that defines a substantially uniform cross-section corresponding to that of the cutting tool""s shank. To properly gauge the distance between each cutting tool tip and its corresponding receiving bracket, operators of stump grinding machines utilizing conventional cutting tools and brackets must utilize a separate gauging bar or other measurement device. The measured depth must then be maintained while tightening the receiving bracket on the cutting wheel.
In addition to these conventional cutting tools, several other types of cutting tools exist in the art. In one case, a large cutting tool defines a dimpled portion that engages with a protrusion defined on the corresponding receiving bracket. In another design, the bracket and the cutting tool are simply made of a unitary construction. However, these prior art designs are larger, heavier, and generally more expensive than conventional cutting tools. For example, the dimpled cutting tool requires use of a special corresponding bracket that would not work well, if at all, with any other type of cutting tool.
The present invention recognizes and addresses the foregoing considerations, and others, of prior art constructions and methods. Accordingly, it is an object of the present invention to provide a novel stump grinding machine.
It is a further object of the present invention to provide a stump grinding machine having improved cutter tools mounted to the cutting wheel.
It is a more particular object of the present invention to provide a novel stump cutter tool which facilitates ease of mounting to the grinding wheel.
Some of these objects are achieved by a stump grinding wheel including a wheel member having a plurality of receiving brackets. Each bracket includes a cutting tool channel for receipt of a respective cutting tool. Each cutting tool includes an elongated shaft having a base end and a distal end, and a cutting tip at the distal end. A stop is defined on the elongate shaft between the base end and the distal end and is configured so that it permits gauging of the distance between the receiving bracket and the cutting tip.
In one exemplary embodiment, the stop is defined on one surface of the elongated shaft. The elongate shaft may include a first side surface, a second side surface, a front surface, and a rear surface. In one preferred embodiment, the stop is defined on the front surface. At least a portion of the front and rear surfaces may be parallel, and at least a portion of the first side surface and second side surface may also be parallel. The cutting tip may be defined on the front surface and it can be angled with respect to a longitudinal axis of the cutting tool. The elongate shaft may define a bend between its base end and its distal end, and the stop may be defined between the bend and the distal end.
Preferably, the wheel member rotates about a wheel shaft and each receiving bracket is configured on the wheel member so that the base ends of the cutting tools are closer to the cutting wheel shaft than the distal ends. In one embodiment, the bracket channel defines a longitudinal axis that is defined completely within a plane that extends completely through an axis of the wheel shaft. The stump grinding wheel can be powered by a power transmitting means between the wheel member shaft, an idler shaft, and an engine mounted on a turntable assembly. The turntable assembly may be mounted to a frame that is supported by at least one wheel. In one embodiment, the stop includes a generally planar surface that extends generally perpendicular to a longitudinal axis of the elongated shaft.
Other objects of the invention are achieved by a stump grinding wheel having a wheel member rotatably mounted about a wheel member shaft. A plurality of receiving brackets are mounted to the wheel member, each receiving bracket includes a channel and holding means for holding the receiving brackets to the wheel member. A means for cutting a tree stump is received in each respective receiving bracket, the cutting means includes means for gaugably mounting the cutting means to the wheel member.
In one preferred embodiment, the stump cutting means includes a plurality of cutting tools and each cutting tool includes an elongated shaft having a base end and a distal end, and a cutting tip at the distal end. A ledge is defined on the elongated shaft between the base end and the distal end and is configured so that the ledge permits gauging of the distance between each receiving bracket and its respective cutting tip. The cutting tool elongated shaft base end may be slidably received within a respective bracket channel.
Other objects of the present invention are achieved by an independently gaugable cutting tool for use with a receiving bracket having a channel and mounted on a cutting wheel of a stump cutting apparatus. The cutting tool includes an elongated shaft generally correspondingly shaped to the bracket channel and defines a base end and a distal end. The base end defines a generally uniform cross-section for at least a portion thereof to permit slidable receipt of the cutting tool between the receiving bracket and the cutting wheel. A cutting tip is defined at the distal end, and a ledge is defined on the elongated shaft between the base end and the distal end and is configured so that it engages the receiving bracket to permit gauging of the distance between the receiving bracket and the cutting tip.
Still further objects are achieved by a stump cutting apparatus including a frame structure supported by at least one wheel and an engine supported by the frame. A boom is pivotally mounted to the frame and has a proximal end and a distal end. A cutting wheel is rotatably mounted to the distal end of the boom and includes a first side surface and a second side surface. A plurality of receiving brackets are mounted to the cutting wheel first and second side surfaces. Each bracket includes a channel for receipt of a cutting tool and a stop ledge adjacent to the channel. Each cutting tool includes an elongated shaft generally correspondingly shaped to the channel and has a base end and a distal end, and a cutting tip defined at the distal end. Each cutting tool also includes means for independently gauging the distance between each receiving bracket stop ledge and a respective cutting tip defined thereon.
In one preferred embodiment, the cutting tool independent gauging means includes a ledge defined on the elongated shaft between the base end and the distal end and is configured so that the ledge engages the bracket stop ledge.
Other objects, features and aspects of the present invention are discussed in greater detail below. The accompanying drawings are incorporated in and constitute a part of the specification, and illustrate one or more embodiments of the invention. These drawings, together with the description, serve to explain the principles of the invention.